Comparison of Histological Chorioamnionitis in Pre-Term Delivery with and without Pre-Term Rupture of Membrane

Histological chorioamnionitis (HCA) is a histologic response to intra-uterine inflammation that is usually confirmed by pathology examination after pre-term delivery and characterized by acute granulocyte infiltration into the fetal-maternal or fetal tissues. This study aimed to compare the HCA in pre-term delivery with and without pre-term rupture of membrane for assessment of its role on early neonatal outcomes and fetal heart rate patterns.

This case-control study was conducted on placenta, chorionamnion, and cord of 100 cases with and without pre-term rupture of membrane between 28 0/7 and 36 6/7 weeks delivered between March 2018 and February 2021. The kind of delivery, gestational age, neonatal intensive care unit admission, a 5 min Apgar score <7, and fetal heart rate patterns in two groups with and without HCA were assessed.

The odds ratio (OR) for HCA was adjusted for fetal heart rate patterns, gestational age, and delivery mode (vaginal delivery or cesarean section). Vaginal delivery, gestational age, neonatal intensive care unit admission, and a 5 min Apgar score <7 were associated with HCA [OR: 2.4, 95% confidence interval (CI): 1.2-9.5, P < 0.05; OR: 0.8, 95% CI: 0.5-1.1, P < 0.05; OR: 1.1, 95% CI: 0.6-2.1, P < 0.05; and OR: 0.9, 95% CI: 0.7-1.3, P < 0.05), respectively. However, there were no specific fetal heart rate patterns associated with HCA.

Placental histology examination in pre-term infants with low Apgar scores may be useful to investigate the association between neonatal complications in pre-term delivery and asymptomatic chorioamnionitis.